Maintaining an exercise routine while pregnant can significantly increase the success of your pregnancy. The American College of Sports Medicine (ACSM) offers the following recommendations for pregnant exercisers:
Avoid exercising while laying down on your stomach or back
Make sure that you are well hydrated and drink plenty of fluids
Avoid high heat and humidity
Stop exercising if you're fatigued, develop persistent pain or experience any vaginal bleeding
Avoid exposure to extremes of air pressure
Don't increase the intensity of your workout beyond pre-pregnancy levels